Spreading fluid clutch



Oct 9, 1951 H. E. CARNAGUA Erm. 2,570,641

SPREADING FLUID CLUTCH Original Filed Dec. 16, 1945 2 Sheets-Sheet l Oct9, 1951 H. E. CARNAGUA ETAL 2,570,641

ASPREADING FLUID CLUTCH 2 Sheets-Sheet 2 Original Filed Dec. 16, 1943 'Ibiz;

Patented Oct. 9, 1951 SPREADING FLUID CLUTCH Harold E. Carnagua andDonald W. Kelbel,

Muncie, Ind., assignors to Borg-Warner Corporation, Chicago, Ill., acorporation of Illinois Original application December 16, 1943, SeriallNo. 514,464. Divided and this application October 31, 1946, Serial No.706,884

1 Claim.

This invention relates to transmissions and particularly to those whichincorporate fluid operated or controlled devices.

It is an object of orur invention to provide an improved frictioncoupling in a transmission and more yparticularly one which is fluidpressure actuated. It is a more specific object to provide such acoupling which is capable of carrying large loads for its size and tothis end it is an object to provide such a coupling having two movablefriction members one of which has a piston fitting in a recess formed inthe other member, with a fluid connection being provided whereby fiuidunder pressure can be introduced into the recess and behind the pistonfor engaging the friction coupling.

It is also an object of this inventionvto provide Atransmittedr directlytheretov by the power splitting differential II. f

The torque in intermediate structure I2 may be again multiplied lbymeans of planetary gearing I4 to provide a low range operation, or itmay be Y transmitted directly to a driven shaft I5 for high an improvedarrangement of uid conduits bymeans of which such a coupling may beconnected through one of the shafts of the transmission with an outsidesource of iiuid pressure. To this end it is an object to provide ahollow shaft which may be the driving or driven shaft of thetransmission vand on which the friction coupling as well as otherfiluidactuated devices are mounted, with a hollow/plug being inserted in thehollow shaft in order `to form a plurality of fluid con-l duits withinthe shaft.

This application is a division of our copending l application, SerialNo. 514,464, which has matured into Patent No. 2,414,359, issued January14, 1947.

The invention consists of the novel constr.uc"v

tions, arrangements and devices to be hereinafter described and claimedfor Icarrying out :the above stated objects and such other objects aswill appear from the following description of a certain preferredembodiment illustrated in the acsectional vvView of the scription of thetransmission, power from a prime mover, such as an internal combustionengine (not shown) 'is impressed upon an input shaft I0 which isconnected directly to a power splitting differential I I, a portion ofthe power being transmitted mechanically to an intermediate structure orshaft I2 and the remainder being transmitted-to an infinitely variabletorque multiplying device such as a vaned-type hydrodynamic torque rangeoperation. Whether o r not the torque is again multiplied depends uponthe operation of friction clutches IB and II, friction clutch I6 servingto connect shaft I2 to the planetary gear set to eiTect a torquemultiplication and clutch I I serving to connect shaft I2 directly tothe driven shaft I5 when no torque multiplication is desired.

The reaction for torque multiplication is prolvided by, a brake I8 whichhas suitable connections to both the torque converter I3 and .planetarygearset I4. However, a one-way connection I9 is used between brake I8and torque converting device I3 so as t0 permit the entire device I3 torotate forwardly without effecting any torque multiplication when thefluid conditions therein are propitlofusforssuch operation. It iscontemplated that brake I8, when once applied for forward drive, willremain applied, andwsince the connection between brake I8, andplanetarygear set I4 is a ,permanentv connection, clutches I6 and I I aremutually exclusively operable, to

prevent planetary gear set III from being 3locz'ilred up and held inbraked position when direc drive is desired. n,

A direct connection including a ratchet 20 anda shaft 2| is providedbetw n and driven shafts .I0 and I5 in order. engine by turning drivenshaft I A f start. Clutch 20 is automatically eng ged when drive shaftI0 is not rotating and is automatically disengaged when the engine isidling. A,

.For reverse drive, a brake 22 is provided'which is applied to theturbine element of the'vaned torque converter I3 when thereactionelement or stator thereof is not held against rotation by brakeI8. With clutch I6 engaged and clutch` II disengaged it will be observedthat brake 'i2r also provides a reaction element for both'planetary gearsets I I and I4 as well ascausing the turbine and reaction elements ofthe torque converter I3 to exchange functions so that the turbineelement becomes the stator and the stator elementwbecomes the turbine.The result is a reverse drive in driven shaft I5 through the 'converterI3 as will be described in detail hereinafter.

When this transmission is used in an alitomotive vehicle such as apassenger car, for example, it is contemplated that the rear axle ratioin the vehicle will be in the neighborhood of 4.25 to 1 and accordinglyan overdrive mechanism 23 may be used between driven shaft I5 and therear axle to slow down the engine at high vehicle speed.

Referring now to Fig. 2 for a detailed description of the embodiment ofthe elements described in Fig. l, drive shaft I9 is connected to powersplitting differential II by means of a fly-wheel 24 and a drum 25. Thepower splitting differential II is comprised of a ring gear 26 which issecured to drum 25 so as to be rotatable therewith and which meshes withone or more planet gears 21 each of which in turn meshes with anotherplanet gear (not shown). The said other planet gears mesh with a sungear 28. This form of dual planet gearing is well known in the art andits characteristics need not be described in detail here. Planet pinions21 are mounted on a carrier 29 which is connected on one side to a brakedrum 30 and on the other through a concave disc 3I to an inner drum 32.

Torque converter I3 is comprised of a pump element 33 which is bolted tosun gear 28, a turbine element 34 which is splined to drum 32 and astator element 34a which is connected by means of the aforementionedone-way coupling device I9 to a shaft 35. A brake drum 36 is splined tothe right-hand end (Fig. 2) of shaft 35, said drum constituting therotatable element of' brake I8.

'I'he torque multiplying gear set I4 is comprised of a sun gear 31 whichmeshes with a group of planetary gears (not shown) which in turn mesheswith a second group of planetary gears 38 to form a dual planetary gearset of the typel shown at II and used as a power splitting device. Saidsecond group of planetary gears 38 meshes with a ring gear 39 whichdrives output shaft I5 through the web 40. Planet pinions 38 are mountedon a carrier 4I which is splined to the driven element 42 of clutch I6.Said clutch I6 is of the conical type so as to have the greatestcapacity for the smallest area of cooperating friction surfaces. Thedriven element 42 is operated by a piston 43, preferably made ofstampings to reduce its rotational inertia, said piston forming achamber 44 between itself and turbine element 34 into which fluid underpressure may be admitted. The fluid pressure acts in a direction toengage the clutch, and a spring 45, reacting against carrier 4I, servesto disengage the clutch.

Piston 43 is retracted by means of a plurality of springs 46 tensionedbetween the piston and a loop of wire 41 retained in a groove 48 inturbine member 34. Contact between piston 43 and movable element 42 isestablished by means of a friction facing 49 which is riveted to movableelement 42. The flxed element of clutch I6 is comprised of a'ring 58which is also splined to drum 32 and has a conical surface 5I adapted tocooperate with the conical surface on movable element 42, and anotherconical surface 52 which forms one of the axially fixed frictionsurfaces of clutch I1.

The connection between ring gear 39 and turbine element 34 as statedpreviously is effected by means of friction clutch I1. This clutch, inaddition to the fixed conical surface 52, is provided with a second andopposltely inclined surface 53 formed in a ring 54 splined to drum 32.Cooperating with surfaces 52 and 53 are movable elements 55 and 56 whichare so formed that element 55 provides an annular recess and element 56constitutes an annular piston operating in said annular recess. Theannular recess in element is formed by inner and outer substantiallycylindrical surfaces 55a and 55h respectively and a substantially radialsurface 55e connecting the surfaces 55a and 55h, and the element 56 issimilarly shaped with a piston portion to be slidably disposed in theannular recess. Engagement of the clutch is effected by admitting fluidunder pressure into the space 51 formed between the two elements so asto separate said elements, thereby causing the elements to engagesurfaces 52 and 53. Element 55 is provided with lugs 58 which extendinto a slot 59 in forging 40, and piston 56 is likewise provided withlugs 60 which extend into a slot 6I in forging 49 disposed oppositeslofl 59. The clutch is maintained in a retracted position by means of aseries of springs 62 which are tensioned between a pair of hoops 63positioned outside of lugs 58 and 68.

Clutch 20, which it will be recalled is used to start the engine fromthe driven shaft I5, is comprised of a set of ratchet teeth 64 formed ina piston 65 which is keyed to drive shaft I0, and a cooperating set ofratchet teeth 66 formed in the end of shaft I5. Said shaft I5 is boredto receive piston 65. A reclease spring 61 is received in an opening 68and is compressed against an abutment 69 in shaft I0 to tend to maintainclutch 20 in an engaged condition. Thus whenever uid pressure behindpiston 65 is reduced below the force of the spring 61, clutch 29 will beengaged.

Fluid for disengaging clutch 20, for lubricating portions of thetransmission and for filling torque converter I3 is obtained from asuitable source of udunder pressure such as the engine oil pump and isconducted to a conduit 10 formed in housing 1I and leading to an annularspace 12 formed between driven shaft I5 and shaft 35. Said annular space12 is in communication through a conduit 13 with hydraulic torqueconverter I3, a conduit 14, a return conduit 15 and the series ofconduits and spaces shown in Fig. 2 which eventually reach a spacebehind piston 65. Fluid for operating clutch I6 is admitted from thesame source of fluid under pressure through suitable valving (not shown)to a conduit 16 in casing 1I and connecting conduits and spaces as shownin Fig. 2 to the space 44 behind pistons 43. Fluid under pressure foroperating clutch I1 is obtained likewise through suitable valving (notshown) from the same fluid source and conducted through conduit 11 to aseries of connected coni end.

Brakes I8 and 22 are shown to advantage in Fig. 3. Said brakes comprisea cylinder 18 formed in housing 1I in which is a double acting piston19. It will be noted that the cylinder 18 is disposed radially of thebrake drums 36 and 30 and off their peripheries. The ends of cylinder 18are closed off by end plates and 8l and resilient means such as coilsprings 82 and 83 are compressed between pistcn 19 and end plates 8o and8|. The pressure of springs 82 and 83 is not taken directly by piston 19but by apertured stampings 84 and 85 each of which is anchored to apiston rod 86 and 81 respectively. said rods are provided with shoulders88 and 89, respectively, which limit the inward movement of the rods. Inorder to move one of the rods, for example rod 81, outward, fluid underpressure is admitted through a conduit 90 into the opposite half ofcylinder 18 and the fluid then passes through the apertured stamping 84to piston 19, thereby forcing the piston to the right as viewed in Fig.3 against stamping 85 to move rod 81 outward. A similar arrangement ofparts is used to cause piston rod 86 to be moved to the left as shown inFig. 3.

The movement of each rod is transmitted to the respective brakes bysuitable linkage. As an example of one form of linkage, rod 81 isconnected through a pin-and-slot connection 9| to a bell crank 92 whichis pivoted at 93 to an anchor block for a brake band 94. Said brake band94 cooperates with drum 38 of brake I8. A spring 95 tensioned betweenhousing 1I and a lug 98 on band 94 tends to rotate the end securedthereto in a counterclockwise direction as viewed in Fig. 3. Theopposite end 91 of brake band 94 is secured to an anchor block 98 whichis pivotally connected at 99 to a tension rod |00, said rod beingpivoted at its opposite end IOI to bell crank 92; It will be apparentfrom the arrangement of the various links and anchor blocks that whenpiston rod 81 is moved to the right as viewed in Fig. 3 the ends of thebrake band will be drawn together to effect its tightening about itsassociated drum, thereby causing the brake to become operative to arrestthe rotation of shaft 35. It will also be observed that spring 88 incylinder 19 and spring 95 will tend to release the brake. A similararrangement may be used to operate the brake 22.

Details of the overdrive mechanism 28 are not given here since it iscontemplated that the overdrive will be of standard design such as hasbeen on the market for many years.

The transmission herein described provides a definite neutral throughthe disconnection of the turbine element 34 from the planetary gear setIl and hence when properly controlled the transmission will not creep asis customary in hydrodynamic transmissions which are directly connectedto an internal combustion engine. I'he arrangement of parts is such thatalthough the clutch I8 is required to transmit more than engine torqueand hence must be sufficiently large to carry this load it is locatedadjacent the ily-wheel where ample room is available althoughfunctionally it is associe ted directly with the driven shaft. Clutch I1which is reouired to carry only engine torque, is located ariiacentclutch I8 and likewise does not unduly increase the size of thetransmission. Although both clutches may be engaged abruptly, the torqueat all times is transmitted, at least partly, through the torqueconverter I9 which is inherently a shock absorbing device and hence noexcessive shocks will be transmitted to the frame of the vehicle whenthese clutches are operated.

It will be observed that the operating linkages of brakes I8 and 22 areof the servo type, thus requiring less pressure in the operatingcylinders. As the brake bands take hold, they will rock around and lockwith a greater force than that applied by the oil pressure alone.

The improved friction coupling I1 is one which carries a great amount ofpower for the size of the coupling. This, we consider, is due to thetapered friction surfaces and the separable rings 55 and 58 which areseparated to engage thc friction surfaces. The shaft arrangementproviding the fluid conduits from outside of the transmission casing tothe friction coupling as well as to the other clutch I8 and thehydrodynamic torque transmitting device I3 is also a very advantageousarrangement.

We wish it to be understood that our invention is not to be limited tothe specific constructions and arrangements shown and described, exceptonly insofar as the claims may be so limited, as it will be apparent tothose skilled in the art that changes may be made without departing fromthe principles of the invention.

We claim;

A friction type coupling comprising two members to be frictionallyconnected, one of said members having a pair of spaced friction surfacesfacing' each other, the other of said members comprising a hub elementand a pair of rings splined thereto so as to float axially thereupon,each of said pair of rings having a friction surface adapted to engagewith one of said rst named friction surfaces, one of said rings beingformed with an annular channel therein having inner and outersubstantially cylindrical surfaces facing each other and a substantiallyradial surface connecting these surfaces, said other ring being providedwith an annular piston portion disposed within said channel, a fluidseal carried by said piston portion and in sliding contact with saidouter cylindrical surface, a fluid seal carried by said innercylindrical surface and in sliding contact with said piston portion,said hub being formed with a peripheral groove in communication with aplurality of radial openings through said inner cylindrical surface, apair of i'luid seais carried by said hub element on either side of saidperipheral groove for sealingly connecting said hub element and saidinner cylindrical surface, means for introducing fluid under pressureinto said peripheral groove, radial openings and ychannel to separatesaid rings for engaging the friction surfaces thereon with saidfirst-named friction surfaces, and spring means between said rings foryieldingly holding the rings in their disengaged positions HAROLD E.CARNAGUA. DONALD W. KELBEL.

REFERENCES CITED The following references are of record in the ille ofthis patent:

UNITED STATES PATENTS Number Name Date 796.989 Enrico Aug. 15. 1905847,575 Hanson Mar. 19, 1907 1,475,020 Mayer Nov. 20, 1923 1,953,568Rose Apr. 3, 1934 2.064.553 Mack Dec. 15, 1036 2,138,806 Seeley Nov. 15,1938 2,136,971 Fleischel Nov. 15, 1938 2,211,233 Kelley Aug. 13, 19402.273.345 Burrell Feb. 17, 1942 2,291,241 Lawrence July 28, 19422,300,865 Berger Nov. 3, 1942 2,361,120 Peterson -7 Oct. 24, 19442,414,359 Carnagua et al Jan. 14, 1947 FOREIGN PATENTS Number CountryDate 117,487 Australia Sept. 23, 1943 487,959 Germany Dec. 17. 1929

